Many industrial installations require extensive use of above-ground, outdoor pipe systems for handling a wide variety of fluids which are temperature sensitive in the sense that thermal insulation is required or desirable in the attainment of overall fluid handling efficiency. Insulation of such pipe systems, in turn, is most effectively accomplished by suspending each pipe in space from appropriate supports by depending rods connected to the pipe at spaced intervals along the length thereof, placing any of several acceptable insulating materials around the periphery of the pipe and covering the insulation with an impermeable jacketing material such as sheet plastic, stainless steel, fiber reinforced resin, or the like. The jacketing functions primarily to protect the insulation from deterioration from impregnation of dust and/or water as well as from physical damage.
With all such available insulation jacketing, particularly in outdoor pipe installations, a serious problem is presented by the presence of vertically-projecting pipe appendages such as hanger rods, valve stems, and the like. Such pipe appendages must project through the insulation and jacketing in a way so as to require a caulking-like sealant between the stem or rod and the pipe jacketing in order to effect a complete hermetic seal. Such sealants, however, even with regular maintenance, deteriorate with age and exposure to result in a leakage point in the context of the overall hermetic seal provided by the jacketing. Moreover, because of the location of the caulking-type seal at the base of the vertically-extending rod or valve stem, the point of leakage is most vulnerable to water running down the surface of the rod or valve stem. As a result of this problem, serious damage is caused both to the insulation underlying the jacket, components entrained in the insulation, and often to the pipe itself. The wetting of insulation in the base of hanger rods, valve stems, and the like, can require replacement of insulation as often as once a year in many industrial installations. Also, because of the toxic nature of the atmosphere in which industrial pipe systems are used, rainwater can become sufficiently corrosive to damage the pipe itself, particularly in the concentrated area underlying a suspension rod, for example. In other types of installations where electrical tracers are embedded in the insulation, the tracers are severely damaged so as to require replacement on a regular basis.
In the past, various patents have issued on devices which attempt to protect valve stems from the intrusion of external elements. For example, U.S. Pat. No. 2,601,840, issued on Jul. 1, 1952 to Smith et al., describes an indicating protective cover for pipe flanges. In this patent, a frustoconical-shaped flexible covering material extends over the valve stem and around the valve body of a non-insulated pipeline. Laces are tied together so as to seal edges of the covering material together.
U.S. Pat. No. 2,737,972, issued on Mar. 13, 1956 to Callery et al., describes a bonnet shield for valves. In this bonnet shield, a small hole is formed at the top of a frustoconical-shaped cover. The edges of the cover are buttoned together so as to cover the valve housing above the valve section of a non-insulated pipeline.
U.S. Pat. No. 3,738,383, issued on Jun. 12, 1973 to W. David, describes a valve housing which is surrounded by a one-piece sheath of elastically distendable material resistant to ambient influences. The hollow interior of the sheath has an interior contour which corresponds to the outer contour of the structure. The sheath tightly encases the structure in surface-to-surface relationship therewith.
U.S. Pat. No. 4,407,324, issued on Oct. 4, 1983 to J. P. Caddell, describes a valve stem cover apparatus for protecting hand operable valves. The valve stem cover has an open-ended nipple section on its upper end for receiving the valve stem therethrough. The nipple is provided with a plurality of laterally projecting ribbed edges. A tubular flexible, rubber-like sleeve section attaches to the nipple for frictionally engaging the ribbed edges. A cap encloses the uppermost second end of the tube section so as to encapsulate the valve stem together with the tube and the valve stem cover.
U.S. Pat. No. 4, 453,562, issued on Jun. 12, 1984 to W. J. Palkovics, describes a rain shield accessory for jacketed insulated pipe installations having vertically projecting rod-like appendages. The rain shield is an inverted funnel-shaped member of resilient sheet material which defines a frustoconical body portion joined at its upper end with a coaxial cylindrical neck portion of the valve stem. The sheet material from which the member is formed is precurled about the axis of the body to provide a voluted overlap particularly in the region of the cylindrical neck portion so that the member can be opened and placed about rod-like appendages of varying diameters.
U.S. Pat. No. 5,368,065, issued on Nov. 29, 1994 to Humpert et al., describes a leak shield for a recessed valve. The shield is of an elastically deformable waterproof material and is formed unitarily with a cup-shaped body generally surrounding the plumbing fixture with an annular bellows-type cuff surrounding the control part and having a rear edge unitarily joined to the body and a front edge fixed to a wall surface at the hole edge.
It is an object of the present invention to provide a sealing device which prevents liquid and chemical intrusion into the insulation material of an insulated pipeline.
It is another object of the present invention to provide a sealing device which effectively seals the valve stem of an insulated valve.
It is another object of the present invention to provide a sealing device which can be easily applied around a cutout region of the insulation surrounding a valve of an insulated pipeline.
It is another object of the present invention to provide a sealing device which is adaptable to and easily applied to various types of valve stems.
It is a further object of the present invention to provide a sealing device which is easy to use, relatively inexpensive, and easy to manufacture.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.